What TUN Mode Does in Clash Meta

If you have just installed a Clash Meta or Mihomo-compatible client on Windows 11, you may notice two switches that appear to do almost the same thing: System Proxy and TUN Mode. They are not interchangeable. System Proxy changes the Windows proxy settings that cooperative applications read. TUN mode creates a virtual network interface and captures traffic at a lower level, allowing Clash to handle applications that never look at the Windows proxy panel.

That distinction explains a common beginner symptom: a browser opens websites correctly after you enable System Proxy, but a game launcher, Git client, PowerShell command, virtual machine, or desktop application still connects directly. The application may use its own networking library, ignore WinINET settings, or open raw TCP and UDP sockets. In those cases, the system proxy switch is working exactly as designed; it simply does not control every connection on the computer.

Clash Meta TUN mode on Windows 11 addresses this gap by placing a virtual adapter between Windows applications and the physical network interface. The Clash core can then inspect the destination, apply your rules, select a proxy group, and forward the traffic through the chosen outbound. When DNS hijacking is configured as well, domain lookups can follow the same policy instead of escaping through the router or internet provider.

TUN mode is therefore broader, not automatically better. It can affect more programs, but it also requires more careful exceptions for local networks, printers, banking portals, captive Wi-Fi pages, and corporate VPN software. The safest setup is one you can explain: know which traffic is captured, which rules send it DIRECT, which domains use a proxy, and how to switch TUN off when diagnosing a Windows networking problem.

Before You Enable TUN Mode

Preparation prevents most failed TUN installations. First, use a current desktop client that actually includes a Mihomo or Clash Meta core. The original Clash for Windows project is archived, and older tutorials often describe menu names or helper components that no longer match maintained clients. The exact interface may differ between Clash Verge Rev, Mihomo Party, Clash Nyanpasu, and other front ends, but the underlying concepts remain the same: a profile, a core, a virtual adapter, routes, and DNS handling.

Import a working subscription or local YAML profile before testing TUN. TUN mode is only a traffic capture mechanism; it does not create proxy servers or repair an invalid configuration. Confirm that the profile contains at least one usable proxy node, that the proxy groups are populated, and that the client can perform a normal latency test. If the profile cannot connect in ordinary system-proxy mode, enabling TUN will add complexity without solving the original problem.

Close other Clash-family applications before continuing. Two clients may compete for the same mixed port, controller port, service helper, or virtual adapter. A previous installation can also leave a background process running after its window has been closed. Check the Windows system tray and exit old clients completely. If you have installed several networking tools, temporarily disable their tunnel functions while configuring Clash so that only one program owns the default route.

Finally, make a note of your current network state. Open a browser and confirm that ordinary internet access works. If you use a work VPN, a Hyper-V virtual switch, WSL2, Docker Desktop, or a manually configured DNS service, record those settings before changing anything. This gives you a reliable comparison point when a new route or adapter changes connectivity.

Administrator Permissions and the Windows Helper

Windows protects route tables, network adapters, and certain service operations from ordinary desktop processes. A Clash client can display a TUN toggle without having the authority to create or control the required helper. When that happens, the switch may immediately turn itself off, show an adapter error, or appear enabled while no traffic reaches the Clash log.

Start by closing the client. Right-click its shortcut or executable and choose Run as administrator. Approve the User Account Control prompt only when you trust the application source. Some clients install a background service or helper the first time TUN is enabled. Read the prompt rather than dismissing it: the helper is normally responsible for privileged networking operations, while the main interface remains a regular desktop process.

If you need to grant elevation every time, open the application properties, select the Compatibility tab, and review Run this program as an administrator. Do not enable compatibility modes at random; they can introduce unrelated behavior. A service-mode option inside the client is usually preferable because it lets the helper start independently and keeps the user interface from holding all administrative privileges.

Security software can also block helper installation. Microsoft Defender may display a notification, while an enterprise endpoint product may silently prevent a service from being created. Do not disable protection globally. Instead, verify the executable source, inspect Windows Security protection history, and request an approved exception if the computer is managed. If the helper was installed but cannot start, open the Windows Services console and look for an entry associated with the client, then check its status and recent event details.

Enable TUN Mode in the Client

Once the client is running with the necessary permissions, open its settings or kernel settings page. Look for a section named TUN, Service Mode, Network Stack, or System Integration. Some interfaces expose a single TUN switch first and place detailed options behind an advanced settings link. Do not confuse a dashboard mode selector such as Rule, Global, or Direct with TUN; those options control rule decisions after traffic has entered the core.

The following configuration is a practical baseline for many Windows 11 installations. Your client may generate these values automatically, and field names can vary by release. If the GUI offers the options, use it first. Edit YAML only when you understand how the client merges overrides with the active profile.

tun:
  enable: true
  stack: mixed
  auto-route: true
  auto-detect-interface: true
  strict-route: false
  dns-hijack:
    - any:53

enable: true activates the feature in the core. The mixed stack is a useful starting point because it can handle common TCP and UDP workloads without forcing you to choose between two extremes. Some systems behave better with system; if mixed produces driver or application-specific problems, test the alternative rather than assuming the profile is broken.

auto-route: true allows the core to add the routes needed for the virtual interface. auto-detect-interface: true helps Clash identify the active physical adapter when a laptop moves between Wi-Fi, Ethernet, and a dock. The exact behavior depends on the core and client. If you use multiple network interfaces, inspect the generated route table rather than relying on a label in the GUI.

DNS hijacking redirects DNS queries addressed to port 53 into the Clash DNS process. This is important because domain-based rules are easier to apply when Clash controls resolution. It does not mean every DNS design should use fake IP. Choose the DNS enhanced mode offered by your profile or client deliberately, and make sure the DNS server can resolve the proxy server itself. A misconfigured DNS block can make a healthy node look unreachable.

Choose the Stack and Route Options

Windows users sometimes see several stack choices, including system, gVisor, and mixed. There is no universal winner. The system stack often integrates naturally with Windows networking, while mixed can provide broader compatibility for applications using different transport patterns. A specialized stack may isolate traffic more strongly but can expose incompatibilities with antivirus software, virtualization, or games that inspect adapters.

Keep strict route disabled during the first setup unless your client documentation specifically recommends it. Strict routing can prevent leaks in carefully designed environments, but it may also interfere with local gateways, VPN interfaces, virtual machines, or service discovery. First establish a working baseline. Then add stronger route restrictions while monitoring what changes.

Look for an option such as auto-start only after TUN works manually. Automatic startup is convenient, but it can hide whether a failure is caused by boot timing, permissions, a missing service, or the active network interface. Manual testing makes the sequence visible: start the client, enable the helper, activate TUN, then inspect the adapter.

Verify the Windows Virtual Network Adapter

After you click the TUN switch, give Windows a few seconds to create or activate the adapter. Open Settings → Network & internet → Advanced network settings. Depending on the client, the adapter may use a name containing Clash, Mihomo, Wintun, or another project-specific label. It may not look like a normal Wi-Fi connection, and it may show no friendly network name. What matters is that it exists, is enabled, and appears when TUN is active.

You can also open Device Manager and expand Network adapters. A warning icon indicates a driver or installation problem rather than a rule problem. Right-clicking the adapter and choosing Properties can reveal a device status message. Avoid manually deleting the adapter while the client is running; stop TUN first, close the client, and use the client’s own uninstall or repair action when available.

For a command-line view, open PowerShell and run:

Get-NetAdapter | Sort-Object ifIndex | Format-Table ifIndex, Name, Status, LinkSpeed

To inspect routes, use:

Get-NetRoute -AddressFamily IPv4 | Sort-Object RouteMetric, DestinationPrefix

The output will vary between Windows builds and network layouts, so do not copy a random route value from a forum and force it into your system. You are looking for evidence that the virtual adapter is present and that the client has installed routes without removing the gateway required for local access. If the physical Wi-Fi adapter loses connectivity immediately, disable TUN, restore the previous state, and review route and DNS settings before trying another stack.

Run the First Proxy and DNS Test

Do not begin with a complicated application. Start with a simple browser test while watching the Clash connection panel. Enable TUN, select Rule mode, and open a site that should match a known proxy rule. The connection list should show the hostname, the matched rule, the selected proxy group, and the outbound node. If the browser works but the connection list stays empty, the browser may still be using a separate proxy path or cached content; test a fresh domain and inspect the exact process.

Next, test an application that previously ignored System Proxy. A command-line tool is useful because it makes the capture difference obvious. For example, run a normal request and compare it with the Clash connection log:

curl.exe -I https://example.com

Do not use the command result alone to determine the route. A successful response proves connectivity, not whether the request used the intended node. The connection log is the authoritative place to confirm that TUN captured the process and that the expected rule won.

DNS deserves a separate test. Run:

nslookup example.com

Windows may display the local DNS server or a loopback address depending on the client’s design. The important questions are whether the query completes, whether the domain resolves consistently, and whether Clash records a DNS event when its logging view supports that feature. If normal websites load but domain-specific proxy rules never match, investigate DNS mode, fake-IP exclusions, and whether the application is using encrypted DNS outside the operating system.

Common Windows 11 TUN Problems

The TUN Switch Turns Off Immediately

This usually indicates a permission, helper, driver, or configuration issue. Restart the client as administrator, confirm that no second proxy client owns a tunnel, and read the client log immediately after clicking the switch. Messages about access denial point to elevation or security software. Messages about an existing adapter or port suggest a conflict. Messages about invalid YAML require profile validation rather than Windows repair.

If the client installed a service, reboot once after installation. Windows can delay service registration, especially when security software scans the new files. If the switch still fails, temporarily remove custom overrides and test the smallest supported TUN configuration. Once the baseline works, restore DNS and route customizations one at a time.

Internet Access Stops After TUN Starts

A total outage after activation often means the default route was captured but no usable outbound path exists. Check that a proxy group has a selected node and that the node’s server hostname can be resolved. Then try Rule mode with a direct rule for local networks. Some profiles send every destination through a group that is empty, while others contain a broad rule that catches DNS or the proxy server itself.

VPN clients and virtualization software can create legitimate competing routes. If you need a corporate VPN, determine which application should own specific destinations before enabling strict route behavior. For local devices, preserve private ranges such as your home LAN according to your environment. Never blindly paste a “bypass all LAN” block without understanding whether it matches the addresses used by your router, NAS, printer, or internal services.

Websites Fail Because DNS Is Unstable

When DNS is the problem, browsers may report secure connection errors, applications may show timeouts, and the Clash log may contain IP addresses without the expected domain rule. Check whether DNS hijacking is enabled, whether the selected enhanced mode is compatible with the profile, and whether your DNS nameservers are reachable through the chosen route.

Do not add many public DNS servers at random. More servers do not automatically mean better reliability. Start with the client’s documented defaults, add a fallback only when necessary, and exclude domains that must resolve through a local or corporate DNS server. If you use fake IP, review fake-IP-filter entries for banking, gaming, intranet, and other services that are known to reject synthetic addresses.

Games or UDP Applications Behave Differently

TUN can capture traffic that System Proxy cannot, but capture does not guarantee that every game protocol will work through every node. Some games use UDP, region checks, anti-cheat services, or multiple launchers with different destinations. Test the launcher and the game separately. Watch for connection entries from the actual game process rather than assuming that a browser rule covers it.

If a game works only with TUN disabled, compare the profile’s UDP support, rule order, and direct exceptions. Try a conservative stack and avoid changing DNS, route strictness, and proxy group selection at the same time. Some games should remain DIRECT for latency or policy reasons, while their launchers may need a different route. The correct result is not necessarily “all traffic through one proxy”; it is predictable routing for each required service.

A Safe Daily Configuration

Once the first tests pass, make the setup easy to operate. Keep one primary client enabled, give the active profile a clear name, and avoid editing the downloaded subscription directly if the provider refreshes it. Use an override or mixin layer for local rules so updates do not erase your changes. Export a backup of important overrides before upgrading the client or changing the core.

Use Rule mode for normal daily work unless you have a specific reason to use Global mode. Rule mode lets local addresses, domestic services, and selected applications remain direct while sending only matched traffic to the proxy. Global mode can be useful for short troubleshooting sessions, but it makes it harder to tell whether a rule is correct and may create unnecessary latency for local services.

Keep System Proxy enabled only when you need applications that explicitly depend on it. TUN and System Proxy can coexist, but overlapping capture paths can confuse troubleshooting. If an application behaves strangely, test three states in order: both disabled, System Proxy only, and TUN only. Record the result in each state. This simple matrix often reveals whether the problem is the application, the profile, the adapter, or a Windows proxy setting.

Before major Windows updates, note the client version and confirm that your TUN helper is supported by the new build. After an update, verify the adapter, DNS resolution, and one known proxy destination. A short checklist is more reliable than waiting until an important application fails.

Final Verification Checklist

1. Confirm the profile. Make sure the active Clash Meta or Mihomo profile contains working proxies, valid groups, and rules that reference existing group names.
2. Confirm permissions. Verify that the client helper or service installed successfully and that Windows Security or endpoint protection is not blocking it.
3. Confirm the adapter. Check Advanced network settings, Device Manager, or PowerShell to ensure the TUN virtual adapter is present and enabled.
4. Confirm route capture. Open a browser or command-line application and watch the Clash connection log for the actual process and destination.
5. Confirm DNS behavior. Run a DNS lookup, check that it completes, and verify that domain-based rules are matching hostnames as expected.
6. Confirm local access. Test your router, printer, NAS, work VPN, and other local services before declaring the configuration complete.
7. Confirm recovery. Turn TUN off and ensure Windows returns to its ordinary network state. Knowing how to recover is part of a correct setup.

Compared with lightweight proxy switchers and older Windows clients, many alternatives make TUN look like a single magic checkbox, then provide little information when the adapter, DNS path, or helper fails. That can leave beginners guessing whether the problem is permissions, routing, or the subscription itself. Clash Official Site is more useful in this Windows 11 scenario because the Clash Meta workflow exposes those layers clearly: you can inspect the active profile, connection logs, route behavior, and DNS decisions instead of treating the tunnel as a black box. If you want a client and a documented path that you can reproduce on another PC, download Clash Official Site for free and apply the verification steps above one stage at a time.

→ Download Clash for free and start using it.